Field of the Invention
The present invention relates to a pharmaceutical composition for preventing or treating angiogenic diseases including inhibitors of NUP153 gene expression or NUP153 activity as active ingredient and a method for screening an agent for preventing or treating angiogenic diseases.
Background of Technique
Identifying the target protein of a bioactive small molecule is a key step in addressing the mechanism of the compound. Additionally, structural and biological information of a small molecule and its target protein have been applied to the manipulation of biological systems and drug development (Cong et al., 2012; Lindsay, 2003). Indeed, several new functional annotations for disease-related proteins have been successfully defined using bioactive small molecules (Lomenick et al., 2011; Piggott and Karuso, 2008; Sato et al., 2011). For instance, the affinity-based, direct target protein identification of the immunosuppressive agent FK506 (Tacrolimus) characterized FK506 binding protein (FKBP) as an adaptor protein of FK506. The FK506/FKBP complex inhibits the dephosphorylation of nuclear factor of activated T-cells (NFAT) by calcineurin, preventing T-cell activation (Harding et al., 1989; Liu et al., 1991; Siekierka et al., 1989). Owing to this breakthrough, FK506 has been used as a useful chemical genetic probe in calcineurin-mediated signaling and as an immunosuppressive drug in various medical treatments (Furuichi et al., 2003; Jusko et al., 1995). Recent discovery of an antagonist for cytoplasmic dynein from synthetic small molecules using the core structure of the naturally occurring product purealin would be another example of this line of effort (Firestone et al., 2012).
Several cellular target proteins for angiogenesis and their specific inhibitors have been identified. However, recent clinical studies have revealed that inhibition of these target proteins is not sufficient to block the complex biological processes involved in angiogenesis and tumor development. This drawback mainly arises from the diverse genetic heterogeneity in cancer and alternative pathways that lead to drug resistance (Giles et al., 2003; Markman, 2008). Therefore, mining of new therapeutic targets for angiogenesis regulation is crucial to reduce the clinical failure rate of these small molecules and develop better anti-angiogenic therapeutics. Indeed, small molecules with distinct chemical structures identified by phenotype-based angiogenesis screening have provided new target proteins with unknown functions that will eventually provide more options for controlling angiogenesis and its related disorders (Jung et al., 2010; Lin et al., 2008).
R-(−)-β-O-Methylsynephrine (OMe-Syn), a natural small molecule isolated from plants of the Rutaceae family, was reported to inhibit vascular endothelial growth factor (VEGF)-induced angiogenesis in vitro and in vivo (Kim et al., 2010). The simple and unique chemical structure, biological activity, and good membrane permeability strongly implicate OMe-Syn as a useful seed for chemical genetic probe and drug discovery. However, the underlying mechanism regarding on how OMe-Syn suppresses angiogenesis remains to be elucidated. Accordingly, the present inventors have identified the cellular binding protein that is relevant to the anti-angiogenic activity of OMe-Syn. Using a biotinylated affinity probe of OMe-Syn and a T7 phage display of human cDNA-expressed proteome library, the present inventors identified nucleoporin 153 kDa (NUP153) as one of the binding proteins of the compound.
NUP153 is a component of the nuclear pore complex (NPC), which regulates macromolecular transport between the cytoplasm and nucleus as a gated channel (Ahn, 2009; Vasu and Forbes, 2001). Misregulation of this gated channel, including modification of the cargo, changes in nuclear transport machinery, and reformation of NPC itself, might influence cellular function and subsequently lead to tumorigenesis (Kau et al., 2004). Among several nucleoporins (NUPs), NUP153 has been highlighted as a key player in this unique protein complex. NUP153 plays an important role in the export of RNAs and proteins from the nucleus to the cytoplasm (Fahrenkrog et al., 2002). In addition, NUP153 is necessary for regulating basic nuclear localization signal (NLS)-mediated nuclear protein import (Walther et al., 2001). A recent report also highlighted the role of NUP153 in cell cycle regulation (Mackay et al., 2009). However, no report has described the role of NUP153 in angiogenesis. Accordingly, the present inventors have validated the binding of OMe-Syn to NUP153 and investigated the possible biological role of NUP153 in angiogenesis.
Throughout this application, various publications and patents are referred and citations are provided in parentheses. The disclosures of these publications and patents in their entities are hereby incorporated by references into this application in order to fully describe this invention and the state of the art to which this invention pertains.